Field of the Invention
The present invention relates to an enhanced heat dissipation module having multi-layer heat isolation, and in particular to an enhanced heat dissipation module having multi-layer heat isolation, that is characterized in having tight contact and low thermal resistance, large contact area enhancing heat dissipation, and multi-layer heat isolation protection on heat transmission path to the electrical circuit board. Further, it is provided with elastic metal support to prevent deformation of the electrical circuit board, in achieving high reliability, increased MTBF (Mean Time Between Failure) and MTTF (Mean Time To Failure) for the electrical circuit board.
The Prior Arts
In recent years, due to rapid progress and development of computer and information industries, the functions of electronic devices making use of Integrated Circuit (IC) are enhanced significantly. As such, the computation speed of the electronic devices has been rapidly increased, yet the ensuing heat generated is also increased. By way of an example, in case the heat dissipation of a Central Processing Unit (CPU) is not sufficient, then it tends to burn out due to high temperature. Or, even if it is not burned out, yet the heat it generates will cause over heating of other electronic components around, thus adversely affecting their functions, performance and even specifications. Presently, there are quite a lot of heat dissipation solutions for CPU, however the matching solutions are lacking for preventing other electronic components from being aged by CPU heat dissipated, and that has yet to be developed.
In addition, the electronic devices utilized in the Industries are quite different from the consumer electronic devices, they are required to have high reliability and sufficiently long MTBF (Mean Time Between Failure) and MTTF (Mean Time To Failure). In order to meet this demand, the electronic devices utilized in the Industries adopt a “fan-less” heat dissipation solution, rather than taking a moving part approach using fans or hard disk. However, the side effects of the deformation of the electronic circuit board, and shortening of electronic component MTBF (Mean Time Between Failure) and MTTF (Mean Time To Failure) have always been serious concerns for system design in the Industries, and that have been treated as design limitations and not really been solved effectively.
In this respect, refer to FIG. 5 for a plane view of a conduction type heat dissipation structure according to the Prior Art. As shown in FIG. 5, in such a structure, the contact surface of the metal heat conduction plate is pressed against the heat generation surface of CPU, and that is used in combination with a heat pipe to connect to a metal shell (or heat dissipation plate) of high thermal conductivity, to transfer the high heat generated by CPU to a metal shell, to achieve heat dissipation through heat exchange with cold air. However, when the heat generated by CPU is transferred to the metal shell, the metal shell (or heat dissipation plate) replaces CPU to become a new heat source. At this time, due to heat convection (as shown FIG. 5) between this new heat source and other electronic components on the electric circuit board, the MTBF (Mean Time Between Failure) and MTTF (Mean Time To Failure) of those electronic components tend to reduce to half for every increase of 10° C., thus decreasing their system reliability.
Moreover, in order to ensure tight and compact assembly between high heat generation components and metal heat dissipation structure, in assembly, certain amount of stress is designed to be applied on the electric circuit board near CPU, such that the contact surface of the metal heat conduction plate is pressed effectively against the heat generation surface of CPU, to ensure optimal heat dissipation. However, due to the pressure applied, the electric circuit board tends to deform after long period of usage (as shown in dashed line portion of FIG. 5), such that stress is produced inside the soldering tin between the SMD (surface mounted device) components (for example CPU) and the electric circuit board. Even worse, the solder balls between CPU die and CPU substrate tend to crack for subjecting to internal stress for long period of time, thus leading to the unstable connection or even failure of the entire system due to poor contact. Meanwhile, the deformation of the electric circuit board will create contact gaps and the ensuing poor heat dissipation, such that high temperature persists to cause damage to the electric components around, to adversely affect its performance, MTBF (Mean Time Between Failure), and MTTF (Mean Time To Failure).
Therefore, presently, the design and performance of heat dissipation structure is not quite satisfactory, and it leaves much room for improvement.